The present disclosure relates to a three-dimensional interactive display, that is, for example, suitable for a flat panel display which enables multi-touch sensing and three-dimensional gesture recognition.
A multi-touch sensing technology for concurrently recognizing plural contact points is widely utilized in a mobile phone, a flat panel display and the like. However, most multi-touch sensing devices in the past such as a capacitive type multi-touch tablet (see, LEE, S., BUXTON, W., AND SMITH, K. C. 1985. A multi-touch three-dimensional touch-sensitive tablet. In ACM SIGCHI, 21-25), and a touch type multi-touch sensor (see, HILLIS, W. D. 1982. A high-resolution imaging touch sensor. Int'l. J. of Robotics Research 1, 2, 33-44) have no ability to detect a gesture distantly-positioned from a screen. Most three-dimensional gesture recognition devices use a camera to obtain space information. However, when the camera is used, it requires a space between the camera and an object to obtain an image. So, the technology is not suitable for a thin or mobile device such as a flat panel television, a tablet, a mobile phone and a portable game device. In most of the related studies (see, Matthew Hirsch, Douglas Lanman et al. A Thin, Depth-Sensing LCD for 3D Interaction using Light Fields, SIGGRAPH Asia, 2009), the multi-touch sensing and the three-dimensional gesture recognition are enabled by using a liquid crystal display (LCD) as a bidirectional mask, whereby the camera behind a diffuser panel of a back light is capable of obtaining the image of the object disposed at a front of the screen. However, the device also requires a relatively wide space between the display and the camera to obtain the image by the camera, and is therefore not suitable for a thin or mobile device. On the other hand, when an image detection surface is disposed behind the back light, it is difficult to utilize a light emitting diode (LED) as the back light. This is because an LED or organic LED (OLED) substrate is generally opaque. Besides, it may be unable to use the display technologies with higher intensity, higher contrast, wider view angle or higher power efficiency such as an OLED display, a plasma display panel (PDP) and an E ink display.